Seat for a motor vehicle, and motor vehicle equipped with this seat

ABSTRACT

A front seat for a motor vehicle comprises a seat frame ( 10 ) and backrest frame ( 11 ), lower fixing means ( 12, 13 ) for rigidly fixing the backrest frame to a lower structural element ( 2 ) of a passenger compartment, and upper fixing means ( 15 ) for rigidly fixing an upper part of the backrest frame to an upper structural element ( 17 ) of a passenger compartment.

The present invention relates to a seat for a vehicle, and a motorvehicle equipped with this seat.

The front seats of motor vehicles are generally provided with thepossibility of adjusting the position of the seat relative to thestructure of the vehicle and adjusting the angle of a backrest relativeto a cushion. To achieve this, the backrest is connected to the cushionby a connection articulated along a transverse axis and the cushion ismounted on the floor of the vehicle by means of slide bars. Anadjustable seat for a motor vehicle is known from the document FR 2 801851.

Such a seat, however, which has to be resistant in the case of violentimpact of the motor vehicle with an obstacle, has a frame and hingesaccordingly provided which are bulky and heavy. A bulky seat is obtainedwithout, however, obtaining satisfactory rigidity of the seat.

The object of the present invention is a front seat for a motor vehicleallowing the design of a lightweight and slim frame to provide a seatwhich is space efficient and retains a space in a passenger compartment,whilst improving the rigidity and the resistance of the seat.

The object of the present invention is also a front seat for a motorvehicle allowing the protection of the occupants to be improved in theevent of longitudinal or lateral impact sustained by a vehicle or in theevent of the vehicle overturning.

Such a front seat for a motor vehicle comprises a backrest frame, lowerfixing means for rigidly fixing the backrest frame to a lower structuralelement of a passenger compartment, and upper fixing means for rigidlyfixing an upper part of the backrest frame to an upper structuralelement of a passenger compartment.

The upper and lower fixings of the backrest frame allow the backrest tobe held in place relative to the vehicle structure and thus allow anincrease in the rigidity of the seat as a whole. The seat may beprovided with a slim and lightweight frame without impairing therigidity of the seat or its resistance, in particular in the event ofimpact of the vehicle with an obstacle.

Structural element is understood to be a pillar, a cross-member, a sidemember, a central beam or a sheet metal roof or floor forming thestructure of the vehicle.

Advantageously, the backrest frame and the lower and upper fixing meansare suitable for forming means for rigidifying a passenger compartmentstructure of the vehicle. Thus, the backrest frame connecting a lowerstructural element to an upper structural element of the vehicle allowsthe vehicle structure to be reinforced. The rigidity of the vehicle isimproved, in particular in torsion. The resistance of the passengercompartment in the event of impact is increased and the protection ofthe occupants is improved.

In order to maintain an adjustment of the backrest, backrest upholsterymay be provided mounted vertically mobile on the backrest frame.

In one embodiment, the backrest frame is fixed directly to a lowerstructural element by lower fixing means. A cushion frame may be mountedvertically mobile relative to the backrest frame and/or mobile inrotation along a horizontal axis.

In a further embodiment, a cushion frame is rigidly fixed to thebackrest frame, and the lower fixing means rigidly connect the cushionframe to a lower structural element of a passenger compartment, thecushion frame, the backrest frame and the lower and upper fixing meansbeing suitable for forming means for rigidifying a passenger compartmentstructure of the vehicle. The cushion and backrest frames may be formedintegrally.

Advantageously, the lower fixing means comprise a single leg supportingthe cushion, said leg able to be rigidly fixed to a lower structuralelement of the passenger compartment. The single leg allows a space tobe created for the feet of passengers located on a row of rear seats.

In one embodiment, the upper fixing means comprise at least one upperarm extending from an upper part of the backrest frame and able to berigidly fixed on the opposing side to an upper structural element of thepassenger compartment.

Advantageously, the seat is provided with at least three fixing pointsfor a seat belt. The rigidity conferred to the seat by the upper andlower fixings allows the backrest to resist the tractive force exertedby the seat belt on the upper part of the backrest when the passenger isprojected forward.

The invention also relates to a motor vehicle comprising at least oneseat according to an aspect of the invention.

The backrest frame of the seat may be rigidly fixed to lowercross-members, to a lower central beam, to a lower side member, and/orto a lower portion of a pillar of the vehicle structure. Similarly, theupper part of the backrest frame may be rigidly fixed to an uppercross-member, to an upper central beam, to an upper side member and/orto an upper portion of a pillar of the vehicle.

With the backrest frame being fixed, and in particular when the seat isintended for the driver, a control unit may be provided which is mobilealong a longitudinal axis relative to the seat in order to allow anadjustment of the driving position.

The present invention and its advantages will be better understood bystudying the detailed description of embodiments made by way ofnonlimiting example and illustrated by the figures, in which:

FIG. 1 shows a schematic view in longitudinal section of the passengercompartment of a motor vehicle provided with a seat according to anaspect of the invention;

FIG. 2 shows a partial transverse sectional view along II-II of thepassenger compartment of a motor vehicle provided with a seat accordingto FIG. 1; and

FIG. 3 shows a schematic lateral view of a seat according to an aspectof the invention.

In FIG. 1, a passenger compartment 1 of a motor vehicle, shownpartially, is defined by a floor 2, an instrument panel 3 provided witha steering wheel 4, a front windshield 5 and a roof 6. A front driverseat, denoted by 7 in its entirety, is arranged opposite the steeringwheel 4 and located in front of a row of rear seats (not shown).

The seat 7 comprises a cushion 8 and a backrest 9. A frame of the seat 7is shown in solid lines, padding or upholstery of the seat 7 beingdefined by dotted lines.

The frame of the seat 7 comprises a cushion frame 10 extendingsubstantially horizontally and being slightly angled toward the rear anda backrest frame 11 extending substantially vertically and beingsubstantially angled toward the rear. The backrest 11 and cushion 10frames are fixed to one another in a rigid manner. In this case, theframe is in one piece.

The cushion frame 10 is rigidly fixed to the floor 2 by means of lowerfixing means in the form of a central block or central leg 12 and alower plate 13, the leg 12 having an upper end fixed to a central regionof the cushion frame 10 and a lower end rigidly fixed to the lower plate13, the latter being itself rigidly fixed to the floor 2 of thepassenger compartment.

The backrest frame 11 and the cushion frame 10 are connected by a curvedconnecting portion 14 forming a rigid connection between the backrestframe 11 and the cushion frame 10. The backrest frame 11 is provided atits upper end with a fixing arm 15 extending upward from the upper edgeof the support portion 11, the end 16 of the arm 15 opposing the supportportion 11 being rigidly fixed to an upper structural element of thevehicle.

As is more visible in FIG. 2, the upper end of the arm 15 is fixed to anupper side member 17 of the vehicle, i.e. a longitudinal structuralelement of the vehicle defining an upper edge of the roof 6. Thepassenger compartment 1 is limited laterally by a pillar 18 locatedsubstantially to the side of the backrest 9 of the seat 7.

Such a pillar 18, referred to as ‘central pillar’ is generally arrangedbetween a rear door opening and a front door opening formed in thestructure of the vehicle. Such a pillar contributes to the rigidity ofthe structure of the motor vehicle, notwithstanding the openingsrequired to access the front and rear seats.

As appears more clearly in FIG. 2 where the seat 7 has been shownwithout padding, the backrest frame 11 comprises two lateral pillars 19,20, a lower cross-member 21, an intermediate cross-member 22 and anupper cross-member 23. A housing portion 24 is formed at theintersection of the pillar 20 located at the side of the central pillar18 and the upper cross-member 23 of the frame of the support portion 11.The housing portion 24 has the shape of a frame of substantially squaresection allowing a seat belt reel, not shown, to be housed and fixed toform an upper fixing point of a seat belt installed on the seat 7 whichis also provided with lower fixing means in the form of a first fixinglug 21 a provided at the lateral end of the lower cross-member 21, atthe side of the central pillar 18, and a second fixing lug 21 b providedat the opposing end of the lower cross-member 21 of the backrest frame11. The first lug 21 a is provided for permanently fixing one end of aseat belt, the other lug 21 b being provided to fix a mobile fixingdevice of an intermediate portion of the seat belt. A seat beltextending between the different fixing points is schematized indash-dotted lines C.

The backrest frame 11 comprises a substantially vertical limb 25connecting the arm 15 to the frame 24 and an oblique limb 26 connectingthe arm 15 substantially at the center of the upper cross-member 23 ofthe support portion 11.

It is understood that the seat, provided that the frame and the fixingsare appropriate, i.e. that they are sufficiently resistant, contributesto the increase in the rigidity of the structure of the vehicle byforming a rigidifying element between a lower structural element and anupper structural element. If the rigidity conferred by the seat to thestructure is sufficient, the central pillar may be eliminated which isthen replaced by the seat frame. Thus, access to the seats is opened upand facilitated for the passengers.

Naturally, the seat cushion frame, instead of being fixed to a floor 2,may be fixed to lower rigidifying cross-members (not shown) arrangedtransversely across the floor. An oblique or horizontal leg is alsoconceivable, connecting one side of the cushion frame to a lowercross-member, to a lower end of the vertical pillar, to a lower centralbeam or to a lower side member (not shown) to open up even more spaceunder the seat for the feet of the passengers. Similarly, it could beprovided that the arm 15 is fixed by its upper end to a differentelement from a side member, such as an upper central beam, an upperrigidifying cross-member. (not shown), an upper end of the pillar 18 ordirectly to the roof 16.

In FIG. 3, where the reference numerals for the elements which aresimilar to those of FIGS. 1 and 2 have been repeated, a seat 7 comprisesa backrest 9 comprising a backrest frame 11 provided with an arm 15,rigidly fixed to a side member 17 of an upper part of the structure of amotor vehicle. The backrest frame extends downward by means of a lowerextension 27 which is rigidly connected to a floor 2 of the motorvehicle. Backrest upholstery 28 is provided on one side of the backrestframe 11. This upholstery may be fixed to the cushion frame 11, or maybe vertically displaceable, as illustrated by the arrow D.

The seat 7 further comprises a cushion frame 10 comprising an end fixedto the backrest frame 11 below the backrest upholstery 28 and extendingsubstantially perpendicularly to the backrest frame 11. The cushionframe 10 carries cushion upholstery 29 on an upper surface. The cushionframe 10 may be rigidly fixed to the backrest frame 11, for example bybeing formed integrally therewith, or mounted mobile along a horizontalaxis 30 (perpendicular to the plane of FIG. 3) so as to allow anadjustment of the angle of the cushion or to push the cushion againstthe backrest, in a movement indicated by the arrow R.

A foldable leg may possibly be provided allowing one free end of thecushion to be supported in the position of use, as shown in dotted linesby the reference numeral 31 and by the arrow P on FIG. 3.

It may also be provided that the cushion frame 10 is mounted verticallymobile, according to the arrow D, on the backrest frame 11 so as toallow an adjustment of the height of the cushion.

In this embodiment, the backrest frame is fixed directly in a rigidmanner to the upper and lower elements of the structure of the vehicle,such that the backrest frame itself may contribute to the reinforcementof the structure of the motor vehicle.

In this case also, the backrest frame of the seat, instead of beingfixed to a floor 2, may be fixed to lower rigidifying cross-members (notshown) arranged transversely across the floor. A lower oblique orhorizontal extension 27 is also conceivable, connecting the backrestframe to a lower cross-member, to a lower end of the vertical pillar, toa lower central beam or to a lower side member (not shown), to open upeven further the space below the seat for the feet of the passengers.Similarly, it could be provided that the arm 15 is fixed by its upperend to a different element from the side member, such as an uppercentral beam, an upper rigidifying cross-member (not shown), an upperend of the pillar 18 or directly to the roof 6.

As a result of the invention, a seat is obtained allowing the weight ofthe frame of a seat to be reduced whilst increasing the rigidity of theseat, in particular in the event of impact. The frame of the lightweightseat allows the habitable space of a passenger compartment of the motorvehicle to be maintained, in particular for the rear passengers. Theseat may be used to rigidify the structure of the motor vehicle in itsentirety.

1. A front seat for a motor vehicle, said seat comprising: a backrestframe, lower fixing means for rigidly fixing the backrest frame to alower structural element of a passenger compartment, and upper fixingmeans for rigidly fixing an upper part of the backrest frame to an upperstructural element of a passenger compartment.
 2. The seat as claimed inclaim 1, wherein the backrest frame and the lower and upper fixing meansare suitable for forming means for rigidifying a passenger compartmentstructure of a vehicle.
 3. The seat as claimed in claim 1, furthercomprising backrest upholstery mounted vertically mobile on the backrestframe.
 4. The seat as claimed in claim 1, further comprising a cushionframe vertically displaceable relative to the backrest frame.
 5. Theseat as claimed in claim 1, further comprising a cushion frame mobile inrotation along a horizontal axis relative to the backrest frame.
 6. Theseat as claimed in claim 1, further comprising a cushion frame rigidlyfixed to the backrest frame wherein the lower fixing means rigidlyconnect a cushion frame to a lower structural element of a passengercompartment, the cushion frame, the backrest frame and the lower andupper fixing means being suitable for forming means for rigidifying apassenger compartment structure of the vehicle.
 7. The seat as claimedin claim 6, wherein the cushion and backrest frames are formedintegrally.
 8. The seat as claimed in claim 6, wherein the lower fixingmeans comprise a single leg supporting the cushion frame, said leg ableto be rigidly fixed to a lower structural element of the passengercompartment.
 9. The seat as claimed in claim 1, wherein the upper fixingmeans comprise at least one upper arm extending from an upper part ofthe backrest frame and able to be rigidly fixed on the opposing side toan upper structural element of the passenger compartment.
 10. The seatas claimed in claim 1, comprising at least three fixing points for aseat belt.
 11. A motor vehicle comprising at least one seat as claimedin claim
 1. 12. The vehicle as claimed in claim 11, wherein the lowerfixing means are rigidly fixed to lower cross-members, to a lowercentral beam, to a lower side member and/or a lower portion of a pillarof the vehicle structure.
 13. The vehicle as claimed in claim 11,wherein the upper fixing means are rigidly fixed to an uppercross-member, to an upper central beam, to an upper side member and/orto a lower portion of a pillar of the vehicle structure.
 14. The vehicleas claimed in claim 11, further comprising a control unit mobile along alongitudinal axis relative to the seat.